#!/usr/bin/env bash

# SPDX-FileCopyrightText: 2022 Caleb La Grange <thonkpeasant@protonmail.com>
# SPDX-License-Identifier: GPL-3.0-only

Print_help(){
	cat <<- EOF
	Usage: ./download gitmodule [name]

	Options:
	name: The name of the module as specified in resources/git/revisions file
	EOF
}

Fail(){
	printf "${@}\n"
	Print_help
	exit 1
}

Check_vars(){
	if [ -z "${revision+x}" ]; then
		Fail 'Error: revision not set'
	fi
	if [ -z "${location+x}" ]; then
		Fail 'Error: location not set'
	fi
	if [ -z "${url+x}" ]; then
		Fail 'Error: url not set'
	fi
}

Patch(){
	for patchfile in ${PWD}/${patchdir}/*.patch ; do
		( cd ${tmp_dir}
		git am ${patchfile} || return 1
		)
	done
}

Run(){
	git clone ${url} ${tmp_dir} || git clone ${bkup_url} ${tmp_dir} || Fail "ERROR: couldn't download ${name}\n Check Network connection"
	( cd ${tmp_dir} && git reset --hard ${revision} )
	patchdir="resources/${name}/patches"
	
	if [ -d "${patchdir}" ]; then
		Patch || Fail "ERROR: Faild to patch ${name}"	
	fi
	
	mv ${tmp_dir} ${location} || Fail "ERROR: couldn't copy temp to destination\n ${tmp_dir} > ${location} check permissions"
}

if [ -z "${1+x}" ]; then
	Fail 'Error: name not set'
else
	name=${1}
fi

while read -r line ; do
	set ${line} >/dev/null 2>&1
	case ${line} in
		rev:*)
		revision=${2}
		;;
		loc:*)
		location=${2}
		;;
		url:*)
		url=${2}
		;;
		bkup_url:*)
		bkup_url=${2}
		;;
	esac
done <<< $(eval "awk ' /\{.*${name}.*}{/ {flag=1;next} /\}/{flag=0} flag { print }' resources/git/revisions")

Check_vars
tmp_dir=$(mktemp -dt "${name}_XXXXX")

# clean out old version just in case
if [ -d "${location}" ]; then
	rm -rf ${location}
fi

Run

# clean in case of failure
rm -rf ${tmp_dir} >/dev/null 2>&1
